fix: handle megatron nvrx AssertionError and bump nvidia-resiliency-ext>=0.6.0

megatron-core raises AssertionError (not ImportError) at import time when
nvidia-resiliency-ext<0.6.0 is installed. Adding AssertionError to the
except clause in deploy_ray.py lets the existing HAVE_RAY=False fallback
handle this gracefully, fixing test_deploy_ray.py collection errors in CI.
Also bumps the override pin from >=0.3.0,<=0.6.0 to >=0.6.0.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Onur Yilmaz <oyilmaz@nvidia.com>

Author: oyilmaz-nvidia

nemo_deploy/deploy_ray.py

@@ -30,7 +30,7 @@
     from nemo_deploy.multimodal.megatron_multimodal_deployable_ray import MegatronMultimodalRayDeployable
 
     HAVE_RAY = True
-except (ImportError, ModuleNotFoundError):
+except (ImportError, ModuleNotFoundError, AssertionError):
     from unittest.mock import MagicMock
 
     ray = MagicMock()